Which of the following insects has shown the least widespread development of resistance to DDT?
According to WHO guidelines, what is the recommended minimum air change rate per hour in isolation rooms for airborne infection control?
Which of the following gases is a significant contributor to the greenhouse effect?
At what stage does the contraction of a family typically begin?
Which field of study focuses on person-to-person inter-relationships in a society?
In the ESI programme, employers and employees in the organized sector contribute to the fund. What is the employer's contribution?
What is the common threshold for statistical significance in hypothesis testing?
Spot map is used for?
In a clinical study examining the relationship between weight and height in pediatric patients, what is the maximum possible value of the correlation coefficient if the correlation is very strong?
What is the type of sampling used when a random sample is taken from distinct groups within a population, such as religious groups like Hindus, Muslims, and Christians?
NEET-PG 2013 - Community Medicine NEET-PG Practice Questions and MCQs
Question 71: Which of the following insects has shown the least widespread development of resistance to DDT?
- A. Mosquitoes
- B. Fleas
- C. Tsetse flies (Correct Answer)
- D. Ticks
Explanation: ***Tsetse flies*** - **Tsetse flies** have shown the least widespread development of **resistance to DDT**, likely due to their specific life cycles and limited exposure in widespread application campaigns. - This has made DDT, or its successor compounds, remain effective in certain tsetse control programs where other insects have developed high resistance. *Mosquitoes* - **Mosquitoes** have developed **widespread resistance to DDT** globally, significantly impacting malaria control efforts. - Their rapid breeding cycles and extensive exposure to DDT over decades led to the selection and proliferation of resistant strains. *Fleas* - **Fleas** have also developed **significant resistance to DDT**, especially in regions where it was heavily used for pest control in homes and livestock. - This resistance is a major factor in the continued prevalence of flea-borne diseases in certain areas. *Ticks* - **Ticks** have shown considerable development of **resistance to DDT** and other acaricides due to widespread use in livestock and agricultural settings. - Their resistance has complicated efforts to control tick-borne diseases and protect animal health.
Question 72: According to WHO guidelines, what is the recommended minimum air change rate per hour in isolation rooms for airborne infection control?
- A. 2-3 air changes per hour
- B. 4 air changes per hour
- C. 1 air change per hour
- D. More than 6 air changes per hour (Correct Answer)
Explanation: ***More than 6 air changes per hour*** - The World Health Organization (WHO) recommends a **minimum of 6 air changes per hour (ACH)** for airborne precaution rooms, particularly for naturally ventilated settings. - For mechanical ventilation systems, **WHO recommends 12 ACH** for airborne infection isolation rooms to effectively dilute and remove airborne infectious particles. - This higher rate ensures adequate ventilation to reduce the concentration of airborne pathogens like tuberculosis, measles, and varicella. - The WHO guidelines on Natural Ventilation for Infection Control in Health-Care Settings (2009) specify these minimum rates for effective airborne infection control. *2-3 air changes per hour* - An air change rate of **2-3 ACH** may be acceptable for general patient rooms or outpatient areas with natural ventilation in resource-limited settings. - However, this rate is **insufficient for airborne infection isolation rooms** where higher-risk procedures are performed or patients with confirmed airborne infections are housed. - This low rate does not provide adequate dilution of infectious aerosols for airborne precautions. *4 air changes per hour* - While **4 air changes per hour** provides better ventilation than 2-3 ACH, it still falls **below the WHO minimum recommendation of 6 ACH** for airborne infection isolation. - This rate might be acceptable for general wards but is inadequate for dedicated isolation rooms requiring airborne precautions. *1 air change per hour* - An **air change rate of 1 per hour** is completely insufficient for any healthcare infection control measures. - This extremely low rate would lead to dangerous accumulation of infectious particles, significantly increasing transmission risk. - Such minimal ventilation is unacceptable even for general patient care areas.
Question 73: Which of the following gases is a significant contributor to the greenhouse effect?
- A. CO2
- B. Methane
- C. Sulfur hexafluoride
- D. All of the options (Correct Answer)
Explanation: ***All of the options*** - All listed gases (CO2, Methane, and Sulfur hexafluoride) are recognized as significant **greenhouse gases**, contributing to the **greenhouse effect** and **climate change**. - While they differ in their **global warming potential** and atmospheric lifetimes, each plays a role in trapping heat in the Earth's atmosphere. *CO2* - **Carbon dioxide** is a major greenhouse gas, primarily from the burning of **fossil fuels** and deforestation. - It is often considered the most significant contributor due to its high atmospheric concentration and long-term effects. *Methane* - **Methane** is a potent greenhouse gas, with a much higher **global warming potential** per molecule than CO2 over a shorter timescale. - Its sources include agricultural activities (livestock, rice cultivation), natural gas leaks, and landfills. *Sulfur hexafluoride* - **Sulfur hexafluoride** is a synthetic greenhouse gas with an extremely high **global warming potential** and a very long atmospheric lifetime. - Although its atmospheric concentration is lower than CO2 or methane, its potency makes it a significant contributor in specialized industrial applications.
Question 74: At what stage does the contraction of a family typically begin?
- A. Marriage
- B. Birth of the first child
- C. Birth of the last child
- D. Leaving home of the first child (Correct Answer)
Explanation: ***Leaving home of the first child*** - The **departure of the first child** from the home marks the beginning of the **contraction phase** of the family life cycle. - This stage signifies a decrease in the number of active family members residing in the home, initiating the process of family shrinkage. *Marriage* - Marriage is the **initial stage** of the family life cycle, where a new family unit is formed, typically referred to as the **establishment phase**. - This phase focuses on **role adjustment** and bonding, not the contraction of the family size. *Birth of the first child* - The birth of the first child marks the beginning of the **expansion stage** of the family life cycle. - This stage is characterized by an **increase in family size** and the establishment of parental roles. *Birth of the last child* - The birth of the last child typically represents the **end of the expansion phase** and the beginning of the **stable or child-rearing phase**. - While it caps the increase in family size, it doesn't initiate the contraction, as all children are still living at home.
Question 75: Which field of study focuses on person-to-person inter-relationships in a society?
- A. Economics
- B. Psychology
- C. Anthropology
- D. Sociology (Correct Answer)
Explanation: ***Sociology*** - **Sociology** is the scientific study of **society**, patterns of **social relationships**, social interaction, and culture. - It directly addresses **person-to-person inter-relationships** by examining groups, organizations, and societies, and how individuals interact within these structures. *Economics* - **Economics** primarily deals with the production, distribution, and consumption of goods and services, and the management of **scarce resources**. - While it involves human interaction, its focus is on **market dynamics** and resource allocation rather than social relationships themselves. *Psychology* - **Psychology** is the scientific study of the **mind and behavior**, focusing on individual thought processes, emotions, and individual responses. - It examines human behavior at the **individual level**, rather than the broader societal inter-relationships between people. *Anthropology* - **Anthropology** is the study of **humanity**, especially focusing on human societies and cultures and their development. - While it examines human social structures, its scope is often broader, encompassing **cultural evolution** and diverse societies rather than the specific patterns of inter-relationships within a single society like sociology.
Question 76: In the ESI programme, employers and employees in the organized sector contribute to the fund. What is the employer's contribution?
- A. 1.75%
- B. 4.75% (Correct Answer)
- C. 3.25%
- D. 2.75%
Explanation: ***4.75%*** - The **Employees' State Insurance (ESI) program** is an integrated social security scheme designed to protect workers in the organized sector. - As of 2019, the employer's contribution rate to the ESI fund is set at **4.75%** of the employee's gross wages, while the employee contributes 0.75%. *3.25%* - This percentage is **not the current employer contribution rate** for the ESI scheme; it is higher than the employee's contribution but less than the actual employer's share. - Prior to 2019, the employer's contribution was 4.75% and the employee's contribution was 1.75%, which sums up to 6.5%. The figures were revised on 13.06.2019 reducing the overall contribution from 6.5% to 4%. *2.75%* - This is not the current contribution rate for either the employer or the employee under the ESI program; it falls outside the established percentages. - The ESI scheme ensures compliance through fixed statutory contributions from both parties, which are not represented by this figure. *1.75%* - This was the **employee's contribution rate** to the ESI fund prior to the 2019 revision, not the employer's. - The current employee contribution rate is significantly lower at 0.75%.
Question 77: What is the common threshold for statistical significance in hypothesis testing?
- A. 0.01
- B. 0.02
- C. 0.03
- D. 0.05 (Correct Answer)
Explanation: ***Correct: 0.05*** - A **p-value of 0.05 (or 5%)** is the most widely accepted and **conventional threshold** for statistical significance in most scientific fields, including medicine - This represents a **5% probability** of observing the results if the **null hypothesis** were true (Type I error or α level) - This is the **standard alpha level** taught in biostatistics and most commonly used in medical research *Incorrect: 0.01* - While 0.01 indicates **higher statistical confidence** (1% chance of Type I error), it is more stringent than the standard threshold - Used in studies requiring **greater certainty** or where false positives have severe consequences - Not the most common or default threshold in general hypothesis testing *Incorrect: 0.02* - A p-value of 0.02 represents a **2% chance of Type I error** - While statistically valid, it is **not a conventional alpha level** for most hypothesis tests - Not the standard threshold taught or applied in medical statistics *Incorrect: 0.03* - A p-value of 0.03 represents a **3% chance of Type I error** - This is **not a standard choice** for statistical significance testing - Not the conventionally prescribed alpha level in biostatistics
Question 78: Spot map is used for?
- A. Local distribution of disease (Correct Answer)
- B. Rural-urban variation
- C. National variation
- D. None of the options
Explanation: ***Local distribution of disease*** - A **spot map** visually represents the geographic distribution of individual cases of a disease or health event. - Each 'spot' on the map corresponds to the exact location where a case occurred, making it ideal for identifying **clusters** or patterns of disease within a specific area. *Rural-urban variation* - While a spot map could potentially show cases in both rural and urban settings, its primary purpose is not to specifically highlight the differences between these two broad categories. - Other types of **thematic maps** or **statistical analyses** are better suited for assessing rural-urban variations. *National variation* - A spot map would be impractical for showing national variation in detail, as it would require plotting individual cases across an entire country, leading to an overly cluttered and uninterpretable image. - **Choropleth maps**, which use shading or colors to represent data for predefined geographic areas (like states or provinces), are more appropriate for illustrating national trends or variations. *None of the options* - This option is incorrect because the primary use of a spot map aligns directly with illustrating the **local distribution of disease**.
Question 79: In a clinical study examining the relationship between weight and height in pediatric patients, what is the maximum possible value of the correlation coefficient if the correlation is very strong?
- A. 0
- B. +1 (Correct Answer)
- C. +2
- D. No correlation
Explanation: ***+1 (perfect positive correlation)*** - A correlation coefficient of **+1** indicates a perfect positive linear relationship between two variables, meaning as one variable increases, the other increases proportionally. - This value represents the **maximum possible strength** for a positive correlation. *0* - A correlation coefficient of **0** indicates no linear relationship between two variables. - This would contradict the premise that the correlation is "very strong". *+2 (invalid value for correlation coefficient)* - The correlation coefficient, also known as Pearson's r, can only range from **-1 to +1**. - A value of +2 is outside this possible range and is therefore an **invalid value**. *No correlation (not possible for strong correlation)* - **No correlation** implies a correlation coefficient of 0 or close to 0. - This directly contradicts the statement that there is a **very strong correlation** between weight and height.
Question 80: What is the type of sampling used when a random sample is taken from distinct groups within a population, such as religious groups like Hindus, Muslims, and Christians?
- A. Simple random
- B. Stratified random (Correct Answer)
- C. Cluster
- D. Systematic random
Explanation: ***Stratified random*** - This method involves dividing the population into **distinct, non-overlapping subgroups (strata)** based on a shared characteristic (e.g., religious groups). - A **random sample** is then drawn from each stratum, ensuring representation from all groups. *Simple random* - Involves selecting individuals entirely at **random** from the entire population, with each individual having an equal chance of being chosen. - It does not guarantee representation from specific subgroups within the population. *Systematic random* - This method selects individuals at **regular intervals** from a randomly ordered list of the population (e.g., every 10th person). - While it offers a degree of randomness, it does not specifically account for or ensure representation of distinct subgroups. *Cluster* - This method involves dividing the population into **clusters (natural groupings)**, usually geographically, and then randomly selecting entire clusters to sample. - Unlike stratified sampling, where individuals are selected from each stratum, cluster sampling involves sampling all individuals within chosen clusters.